The present invention relates, in general, to intravenous (IV) catheters and, more particularly, to a safety IV catheter with a needle tip protector that will automatically cover the needle tip upon needle withdrawal.
I.V. catheters are used primarily to administer fluids directly into a patient""s vascular system. The catheter is inserted into a patient""s vein by a clinician using a handheld placement device that includes a needle with a sharp distal end. The needle is positioned in the interior hollow portion of the catheter with its sharp distal tip extended slightly beyond the distal edge of the catheter. The proximal end of the needle is connected to a needle hub which is held by the clinician during the insertion procedure.
During the insertion procedure, the clinician inserts the needle and catheter together into the patient""s vein. After insertion of the needle point into the vein, the catheter is forwarded into the vein of the patient by the clinician pushing the catheter with their finger. The clinician then withdraws just the needle by grasping the hub attached to the proximal end of the needle while at the same time applying pressure to the patient""s skin at the insertion site, thus holding the catheter fixed in place. The clinician then typically tapes the proximal end of the now inserted catheter to the patient""s skin and connects the proximal end of the catheter, containing a Luer connector catheter hub, to the source of the fluid to be administered into the patient""s vein.
It is the period of time just as the needle is withdrawn from the catheter that poses great risk to the clinician. The clinician is at risk of an accidental needle stick from the sharp needle which has just been contaminated with a patients blood. This leaves the clinician vulnerable to the transmission of dangerous blood-borne pathogens, including hepatitis and AIDS. The risk of a contaminated needle stick is not isolated just to clinicians. Careless disposal of used needles can put other health care workers at risk as well. Even others outside the health care profession, for example those involved in the clean-up and final disposal of medical waste, are at risk of an accidental needle stick from a carelessly discarded needle.
A number of xe2x80x9csafetyxe2x80x9d IV catheters have been developed to address the issue of accidental needle stick. For example, in U.S. Pat. No. Re. 34,416 to Lemieux, a safety catheter is disclosed which includes an element which covers the needle tip upon removal of the needle from the catheter. The safety element includes a split flange at its proximal end which is expanded by the needle as the needle is inserted into an undersized hole at the center of this flange. The safety element is thus held secure within the catheter hub by inserting the needle through the undersized hole which forces the outside perimeter of the split flange against the inside wall of the catheter hub.
One of the drawbacks to this design is the amount of friction force exerted against the needle by the split flange. A tight fit of the flange against the catheter wall causes great friction against the needle making it difficult to be withdrawn from the catheter by the clinician. A loose fit leaves the flange prone to releasing prematurely from the catheter as the needle is withdrawn, creating the potential that the needle tip will be left exposed.
In U.S. Pat. No. 6,117,108 to Woehr et al, a safety IV catheter is described including a resilient needle guard which protects the needle tip upon removal of the needle from the catheter hub. The needle guard includes an arm that includes an opening through which a needle passes causing radial movement of the arm. This radial movement forces the arm into a groove or behind a rib located on the inside of the catheter hub, capturing the needle guard in the catheter hub. A potential issue with this design develops when the needle guard is not properly seated into the catheter hub. If the distal end of the needle guard arm is not in alignment with the groove in the catheter hub, excessive forces are placed on the needle causing a high drag force as the clinician removes the needle. And, since the needle guard arm is not properly seated in the groove, it may prematurely release from the catheter hub upon the removal of the needle leaving the needle tip exposed.
The prior art safety catheters all exhibit one or more drawbacks that have thus far limited their usefulness and full acceptance by health-care workers. What is needed therefore is a safety IV catheter that functions reliably, is easy and inexpensive to manufacture, and easy to use.
In accordance with the present invention there is provided a catheter and introducer needle assembly including a needle having a diameter, proximal end, attached to a needle hub, a distal end, and a enlarged area disposed therebetween. The assembly further includes a tubular catheter having proximal and distal ends, the introducer needle being coaxially received within the catheter, and a hollow catheter hub having a distal end attached to the proximal end of the catheter and in fluid communication with the catheter. The catheter hub includes an interior having a raised annular rib disposed thereon. The assembly also includes a needle tip protector having a proximal end and a distal end disposed within the catheter hub. The proximal end including at least one unrestrained radially extending lip disposed distal to the annular rib so as to retain the protector within the hub, wherein the distal end of the protector does not abut against the hub interior. The protector having a proximal opening at the proximal end having an unrestrained size greater than the size of the needle diameter and smaller than the enlarged area such that when the needle is removed from the catheter the protector remains attached to the needle.